Sheet feeding device with corner separators



March 21, 1%? w. M. SCHMIDT 3,310,303

SHEET FEEDING DEVICE WITH CORNER SEPARATORS Filed July 51, 1964 5 Sheets-Sheefi 1 INVENTOR.

Wa/demaw M. zfichmldf arch 21, 1967 w. M. scHMmT 3,3fi@,33

SHEET FEEDING DEVICE WITH CORNER SEPARA'I'ORS Filed July 51. .1964 Y 3 Sheets-Sheet 2 I N VENTOR.

ATTORNEYS March 21, 1967 w. M. SCHMIDT SHEET FEEDING DEVICE WITH CORNER SEPARATORS 3 Sheets-Sheet 5 Filed July 31, 1964 INVEN TOR fi/a/dem w" M hizm/af m M m T A United States Patent 3,310,393 SHEET FEEDENG DE'VHCE WITH-I CORNER SEPARATGR Waldemar M. Schmidt, Niles, ilL, assignor to General Binding Corporation, Northfieid, 7th., a corporation of Illinois Filed July 31, 1964, Ser. No. 386,568 1 Claim. (Cl. 271-21) The present invention relates to duplicating and other types of printing machines and is more specifically directed to a sheet separating and sheet feeding apparatus for insuring that individual sheets will be separated and fed off the top of a stack of such sheets irrespective of the quantity, type, and weight of such sheet stock.

Printing and duplicating machines which are designed to produce multiple copies in quick succession from a type set-up or master requires some means or another to insure that a single sheet of paper can be separated from a stack of such sheets and properly fed through the apparatus and that the process can be continued as one sheet after another is fed from the top of the stack.

Various devices known to those skilled in this art have been designed to accomplish this end. Many such devices are quite complex and expensive (those including suction means and the like, for instance) but these do not lend themselves to use in the smaller and less expensive duplicating machines. Prior to the time when sheet separators first came into widespread use, nothing was used to restrain the paper and relatively complex feed wheel mechanisms were required. Such duplicator-s presented undesirable accidental multiple feeding problems which were difficult to overcome.

With the advent of corner separators the sheet separa tion problem was considerably improved but it was still somewhat difiicult to get identical mirror-image alignment of the separators at both sides of the stack since the two separators were rightand left-hand assemblies and mighttherefore be slightly different in configuration with the result that erratic restraint was provided for the paper from one side to the other. Such erratic restraint resulted in improper orientation of the sheet in the duplicator after leaving the separators and other related problems. In addition, some of these types of separators were weighted with the result that the force applied to the sheet corners by the separators varied as the height of the stack varied.

The sheet separating device constructed in accordance with the present invention comprises a feed table having cylindrical corner separators extending upwardly therethrough which contact the leading edges of a plurality of stacked sheets and which have cylindrical outwardly directed lips extending over the topmost sheet on the stack and slightly outwardly of the longitudinal side edges thereof.

The smooth cylindrical configuration of the outwardly directed bent-over lip aids remarkably in improving the operational characteristics of the sheet separator. As the top sheet is thrust forward by the sheet feed mechanism, the leadii'ig edges of the sheet are rolled back gradually forming a smooth, large buckle at the forward end of the sheet with the result that as the leading edges come up'to release point, release is abrupt and substantially simultaneous whereby to insure that the paper will be fed through the duplicator mechanism in properly oriented relation.

It is therefore a principal object of the present invention to provide an improved sheet feeding and corner separating device.

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More specifically, an important object of the invention resides in the provision of a device of the character described in which corner separators are employed which include abutment members with rounded outwardly directed lips extending therefrom in overhanging relation to the side edges of the stack.

Still further, the invention provides a pair of identical corner separators formed from cylindrical stock which have horizontally directed lips extending in overhanging relation to the side edges of the stack with cooperating sheet feeding means contacting the topmost sheet along a line spaced only slightly rearwardly of the separators to provide for even feeding and positive separation of the stacked sheets.

These and other objects, advantages and features of the present invention will become apparent from time to time as the following specification proceeds and with reference to the accompanying drawings, wherein:

FIGURE 1 is a perspective view of a duplicating apparatus incorporating the principles of the present invention;

FIGURE 2 is a fragmentary elevational view taken looking in a direction opposite the direction of sheet feed;

FIGURE 3 is a fragmentary elevational view of the side of the stacked sheets which shows the buckled top sheet illustrated in FIGURE 2;

FIGURE 4 is a plan view of the feed table and cover assembly with part of the table broken away to show the guide rail adjustment means;

FIGURE 5 is a fragmentary side elevational view of a stack of sheets to be fed through the duplicating apparatus and showing the cooperation between the corner separators and the sheet feed roll; and

FIGURE 6 is a side elevational view which is similar in nature to FIGURE 5 but which shows the position of various parts of the assembly when the stack has been reduced to a single sheet.

A duplicating apparatus is shown in FIGURE 1 and comprises generally a housing 10 having a combination feed table and cover assembly 11 pivotally mounted at one end thereof, feed rolls 12, master drum 13, and a combination receiving tray and cover assembly 14- pivotally mounted at the other end thereof for receiving printed sheets.

The combination feed table and cover assembly is pivotally mounted in the housing 10 by a pair of ears 16a and has a pair of parallel upstanding guide rails 15 adjustably mounted on the table portion 16 thereof and knurled adjusting dial 117 is provided as a means for spacing the rails apart a desired distance corresponding to the width of sheets to be fed through the duplicator. In operation, a master sheet is mounted on the drum 13 and the paper feed table 16 is stocked with a stack of paper and the paper feed rolls 12 are positioned on the topmost sheet of the stack. A paper stop 18, which is adjustably mounted on the receiving tray 14, is positioned in accordance with the length of the paper stock to be fed through the apparatus and the crank 19 is then rotated to cause paper to be fed from the table 16 through the unit where printing from the master to the paper is effected and thence to the receiving tray 14.

Turning now to FIGURE 4, it will be observed that the combination feed table and cover assembly includes a cover plate 253 having a pair of spaced upstanding side walls 21 (only one of which is shown in the drawing). A screw shaft 22 is provided with oppositely directed threaded portions 23 and 24 on opposite ends thereof and has radially reduced unthreaded ends 25 journalled within aligned apertures formed in the upstanding sidewalls 21. The knurled dial 117 is mounted on the unthreaded section 25 of the shaft 22 and is fixed for rotatable movc ment therewith by a set-screw 26 whereby to insure that rotation of the knurled dial 17 will effect rotation of the shaft 22.

The feed tray assembly includes feed table 16 which has depending side walls 27 (see FIG. 1) formed integrally therewith and these sidewalls have aligned apertures formed therein which receive the outer ends of the shaft 22. The table 16 is thus pivotally mounted on the cover plate 20 for reasons which Will hereafter become apparent. Right and left centering base members lie along the under surface of the table 16 and are threadedly mounted on the right and left hand threaded sections of the shaft 22 so that rotation of the shaft will cause the centering base members to move toward or away from the center of the shaft an equal distance at an equal rate.

The guide rails 15 each include a horizontally extending section 2? and integral vertically extending portions 3i and are positioned on the table 16 with their horizontal sections 29 in sliding contact therewith. Screws are provided to secure the horizontally extending sections thereof to the ends of the centering base assembly and these screws ride within slots 31 formed in the table 16. Accordingly, by adjustment of the knurled dial 17, the guide rails can be spaced apart a distance approximately equal to the wi th of the paper to be fed through the duplicator and the stack of sheets will be centered in the machine.

The sheet or corner separators 35 constructed in accordance with the principles of the present invention are formed from round wire or cylindrical rod stock and comprise a main shank 3&5 having a right angularly oriented leg 37 extending therefrom and journalled within apertures formed within the centering base assemblies 28 and have upwardly extending curved arms 38 formed at the opposite end thereof.

Torsional centering base springs 39 are mounted on each of the inturned legs 37 of the sheet separators 35 and each has one leg resting against the under surface of the centering base assembly and the opposite leg crimped over the upper surface of the shank 3d of the associated sheet separator whereby to bias the shank 36 of the sheet separators downwardly.

The arms 33 of the sheet separators extend upwardly through small apertures formed in the horizontal sections 29 of the guide rails 15 at the outer ends thereof adjacent the outer edges of the rails. The arms 38 are therefore disposed in the path of movement of the extreme corners of the leading edge of paper fed from the table into the duplicating apparatus.

The outer upper ends of arms 38 are bent outwardly somewhat to define lips 40 which extend over the corners of the topmost sheet on the stack of sheets placed on the table 16 in slightly overhanging relation to the side edges thereof.

A horizontally directed shaft 41 has its ends mounted for movement within arcuate slots 42 formed within the duplicator housing and this shaft has a pair of feed rolls 12 mounted thereon for movement with the shaft. Means are provided for moving the rolls into contact with the uppermost sheet on the stack of sheets mounted on the feed table 16 and for driving the shaft ll so that rotation of the feed rolls 12 will cause the sheet to be fed into the duplicating apparatus.

As will be observed in FIGURES 2 and 3, a stack of sheets 43 is positioned on the table 16 and the guide rail 15 has been moved up to contact or near contact with the side edge of the stack. The feed roll 12 contacts the topmost sheet 43a at a point slightly rearwardly of the leading edge 44 of the stack and the arm 38, being positioned by the centering base assembly and associated guide rail 15 at a point in the path of movement of the extreme end of the leading edge of the stack has its bent-over outwardly extending lip it) bent over the corner of the topmost sheet ,in overhanging relation to the side edges thereof.

Upon rotation of the crank 19 the shaft 41 causes the feed rolls 12 to rotate and thereby tend to push the topmost sheet into the duplicator. The opposed ends of the leading edge of the sheet 43a contact the arm 38, however, and the end of the sheet adjacent the leading edge begins to buckle in the manner shown in FIGURES 2 and 3.

As a direct result of the configuration of the cylindrical rod stock or round wire, and the manner of its disposition relative to the sheet being fed, the corners of the sheet buckle gradually so that when both sides of the sheet finally come up to the release point, they tend to come up to the release point together and release is abrupt, but simultaneous.

The carefully tensioned torsion springs 39 maintain a constant pressure on the arms and thereby insure that the pressure of the arms on the paper stock will be substantiaily constant even though the level of stock on the table 16 varies from that shown in FIGURE 5 to that shown in FIGURE 6. These latter two figures show the relationship of the separators 35 and feed rolls 12 to the stock as the supply of stock diminishes.

Lastly, it will be observed that a tensioned torsion spring $5 is positioned at each end of the shaft 22 with one leg engaging the cover plate 29 and its opposite leg engaging the under surface of the table 16 whereby to bias the ends of the cover plate and table adjacent the corner separators apart. As a consequence of this arrangement, with the table 16 held in fixed position on the laminating apparatus, depression of the scaled section 47 of the cover plate 2% will cause the end of the plate 20 and table 16 adjacent the corner separators to move relatively together and such movement will cause the edge 48 of cover plate 2%) to contact the shanks 36 of separators 35 and pivot the same whereby to space the lips 40 from the surface of the table 16 to permit the insertion of a new stack of sheets.

It will be understood that this embodiment of the invention has been used for illustrative purposes only and that various modifications and variations in the invention may be effected without departing from the spirit and scope of the novel concepts thereof.

I. claim as my invention:

In combination in a duplicating apparatus.

a paper feed table for supporting stack of paper sheets,

spaced guide rails having vertically extending walls and being slidably positioned on said table,

a shaft journalled for rotatable movement within said feed table and having opposed-hand threads on each end thereof,

centering base assemblies threadedly secured to the opposed threaded ends of said shaft and being positioned on the outer surface of said table and attached to said guide rails,

means for rotating said shaft whereby to vary the spacing of said centering base assemblies and thereby vary the spacing between said guide rails in accordance with the width of stacked paper,

corner separators formed entirely of round wire stock and having legs pivotally received within each of said centering base assemblies,

said corner separators having arms connected to and extending from said legs upwardly through said guide rails at points spaced slightly inwardly of said vertical walls and within the path of movement of the leading edge of a sheet fed from the stack,

lips formed integrally with and extending from said arms over the corners of the topmost stacked sheet in slightly overhanging relation to the side edges thereof,

said lips also being formed of round wire stock smoothly finished to reduce friction between the said lips and the paper stock,

spring means engageable with each of said separators and providing a light pressure bias thereto 5 whereby to maintain said lips in light pressure contact with the topmost attached sheet,

a plate pivotally mounted on the under surface of said table and positionable in engagement with each of said separators at points spaced from their respective points of pivotal connection with said centering base assemblies whereby to permit movement of both of said separators by movement of said plate, and

a spring means interposed between said plate and said table and normally biasing said plate out of engagement with said separators.

References Cited by the Examiner UNITED STATES PATENTS ROBERT B. REEVES, Primary Examiner.

0 STANLEY H. TOLLBERG, M. HENSON WOOD, JR.,

Examiners. 

